Reorganize file structure of itest cases

Changes:
* Group tests by shared semantics, rather than having all on top level.
* Remove 2 tests in `builtin.rs` (Vector2, VariantArray), already covered through unit-tests and other itests.

itest/rust/src/callable_test.rs → itest/rust/src/builtin_tests/containers/callable_test.rs

@@ -5,10 +5,10 @@
  */
 
 use godot::bind::{godot_api, GodotClass};
-use godot::builtin::{varray, Callable, ToVariant, Variant};
-use godot::engine::Object;
+use godot::builtin::inner::InnerCallable;
+use godot::builtin::{varray, Callable, GodotString, StringName, ToVariant, Variant};
+use godot::engine::{Node2D, Object};
 use godot::obj::{Gd, Share};
-use godot::prelude::GodotString;
 
 use crate::framework::itest;
 
@@ -105,3 +105,23 @@ fn callable_call_return() {
     // errors in godot but does not crash
     assert_eq!(callable.callv(varray!["string"]), Variant::nil());
 }
+
+#[itest]
+fn callable_call_engine() {
+    let obj = Node2D::new_alloc();
+    let cb = Callable::from_object_method(obj.share(), "set_position");
+    let inner: InnerCallable = cb.as_inner();
+
+    assert!(!inner.is_null());
+    assert_eq!(inner.get_object_id(), obj.instance_id().to_i64());
+    assert_eq!(inner.get_method(), StringName::from("set_position"));
+
+    // TODO once varargs is available
+    // let pos = Vector2::new(5.0, 7.0);
+    // inner.call(&[pos.to_variant()]);
+    // assert_eq!(obj.get_position(), pos);
+    //
+    // inner.bindv(array);
+
+    obj.free();
+}

itest/rust/src/variant_test.rs → itest/rust/src/builtin_tests/containers/variant_test.rs

@@ -4,17 +4,22 @@
  * file, You can obtain one at https://mozilla.org/MPL/2.0/.
  */
 
-use crate::framework::{expect_panic, itest};
+use std::cmp::Ordering;
+use std::fmt::Display;
+
 use godot::builtin::{
     dict, varray, FromVariant, GodotString, NodePath, StringName, ToVariant, Variant, Vector2,
     Vector3,
 };
+use godot::builtin::{
+    Basis, Dictionary, VariantArray, VariantConversionError, VariantOperator, VariantType,
+};
 use godot::engine::Node2D;
 use godot::obj::InstanceId;
-use godot::prelude::{Basis, Dictionary, VariantArray, VariantConversionError};
-use godot::sys::{GodotFfi, VariantOperator, VariantType};
-use std::cmp::Ordering;
-use std::fmt::{Debug, Display};
+use godot::sys::GodotFfi;
+
+use crate::common::roundtrip;
+use crate::framework::{expect_panic, itest};
 
 const TEST_BASIS: Basis = Basis::from_rows(
     Vector3::new(1.0, 2.0, 3.0),
@@ -408,19 +413,6 @@ fn variant_hash_correct() {
 
 // ----------------------------------------------------------------------------------------------------------------------------------------------
 
-pub(crate) fn roundtrip<T>(value: T)
-where
-    T: FromVariant + ToVariant + PartialEq + Debug,
-{
-    // TODO test other roundtrip (first FromVariant, then ToVariant)
-    // Some values can be represented in Variant, but not in T (e.g. Variant(0i64) -> Option<InstanceId> -> Variant is lossy)
-
-    let variant = value.to_variant();
-    let back = T::try_from_variant(&variant).unwrap();
-
-    assert_eq!(value, back);
-}
-
 fn truncate_bad<T>(original_value: i64)
 where
     T: FromVariant + Display,

itest/rust/src/builtin_tests/mod.rs

@@ -0,0 +1,33 @@
+/*
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/.
+ */
+
+mod geometry {
+    mod basis_test;
+    mod plane_test;
+    mod projection_test;
+    mod quaternion_test;
+    mod rect2_test;
+    mod rect2i_test;
+    mod transform2d_test;
+    mod transform3d_test;
+}
+
+mod containers {
+    mod array_test;
+    mod callable_test;
+    mod dictionary_test;
+    mod rid_test;
+    mod signal_test;
+    mod variant_test;
+}
+
+mod string {
+    mod godot_string_test;
+    mod node_path_test;
+    mod string_name_test;
+}
+
+mod color_test;

itest/rust/src/common.rs

@@ -0,0 +1,22 @@
+/*
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/.
+ */
+
+use std::fmt::Debug;
+
+use godot::builtin::{FromVariant, ToVariant};
+
+pub fn roundtrip<T>(value: T)
+where
+    T: FromVariant + ToVariant + PartialEq + Debug,
+{
+    // TODO test other roundtrip (first FromVariant, then ToVariant)
+    // Some values can be represented in Variant, but not in T (e.g. Variant(0i64) -> Option<InstanceId> -> Variant is lossy)
+
+    let variant = value.to_variant();
+    let back = T::try_from_variant(&variant).unwrap();
+
+    assert_eq!(value, back);
+}

itest/rust/src/codegen_test.rs → itest/rust/src/engine_tests/codegen_test.rs

@@ -56,6 +56,13 @@ fn codegen_constants() {
     // assert_eq!(Material::RENDER_PRIORITY_MIN, -128);
 }
 
+#[itest]
+fn cfg_test() {
+    // Makes sure that since_api and before_api are mutually exclusive
+    assert_ne!(cfg!(since_api = "4.1"), cfg!(before_api = "4.1"));
+    assert_ne!(cfg!(since_api = "4.2"), cfg!(before_api = "4.2"));
+}
+
 // ----------------------------------------------------------------------------------------------------------------------------------------------
 
 #[derive(GodotClass)]

itest/rust/src/registration/mod.rs → itest/rust/src/engine_tests/mod.rs

@@ -4,4 +4,6 @@
  * file, You can obtain one at https://mozilla.org/MPL/2.0/.
  */
 
-mod constant_test;
+mod native_structures_test;
+mod node_test;
+mod utilities_test;

itest/rust/src/framework/runner.rs

@@ -16,7 +16,7 @@ use crate::framework::{passes_filter, RustTestCase, TestContext};
 
 #[derive(GodotClass, Debug)]
 #[class(init)]
-pub(crate) struct IntegrationTests {
+pub struct IntegrationTests {
     total: i64,
     passed: i64,
     skipped: i64,

itest/rust/src/lib.rs

@@ -6,45 +6,15 @@
 
 use godot::init::{gdextension, ExtensionLibrary};
 
+mod builtin_tests;
+mod common;
+mod engine_tests;
 mod framework;
-
-mod array_test;
-mod base_test;
-mod basis_test;
-mod builtin_test;
-mod callable_test;
-mod codegen_test;
-mod color_test;
-mod derive_variant;
-mod dictionary_test;
-mod enum_test;
-mod func_test;
-mod gdscript_ffi_test;
-mod init_test;
-mod native_structures_test;
-mod node_test;
-mod object_test;
-mod option_ffi_test;
-mod packed_array_test;
-mod plane_test;
-mod projection_test;
-mod property_test;
-mod quaternion_test;
-mod rect2_test;
-mod rect2i_test;
-mod registration;
-mod rid_test;
-mod signal_test;
-mod singleton_test;
-mod string;
-mod transform2d_test;
-mod transform3d_test;
-mod utilities_test;
-mod variant_test;
-mod virtual_methods_test;
+mod object_tests;
+mod register_tests;
 
 // ----------------------------------------------------------------------------------------------------------------------------------------------
-// API for test cases
+// Entry point
 
 #[gdextension(entry_point=itest_init)]
 unsafe impl ExtensionLibrary for framework::IntegrationTests {}

itest/rust/src/string/mod.rs → itest/rust/src/object_tests/mod.rs

@@ -4,6 +4,8 @@
  * file, You can obtain one at https://mozilla.org/MPL/2.0/.
  */
 
-mod godot_string_test;
-mod node_path_test;
-mod string_name_test;
+mod base_test;
+mod object_test;
+mod property_test;
+mod singleton_test;
+mod virtual_methods_test;

itest/rust/src/derive_variant/mod.rs → itest/rust/src/register_tests/derive_variant/mod.rs

@@ -6,12 +6,13 @@
 
 use std::fmt::Debug;
 
-use crate::framework::itest;
-use crate::variant_test::roundtrip;
 use godot::bind::FromVariant;
 use godot::bind::ToVariant;
 use godot::builtin::{dict, varray, FromVariant, ToVariant, Variant};
 
+use crate::common::roundtrip;
+use crate::framework::itest;
+
 #[macro_export]
 macro_rules! roundtrip_with_skip {
     ($name_to:ident, $name_from:ident, $value:expr, $to_var:expr, $from_var:expr) => {